Analysis of vital statistics, demographic and other population data often leads to important clues linking environmental exposures to specific diseases. The overall objective of this project is to identify and/or confirm the presence of various potential health hazards in the general environment through the mechanism of demographic investigations. Recently completed research includes the development of a statistical model for breast cancer risk which uses vital statistics and other data on breast cancer incidence and published data from several sources on the distributions of known breast cancer risk factors. In addition, the influence of environmental and occupational factors on mortality from chronic renal failure continues to be explored using mortality data for U.S. counties, census data, and data from the NIOSH occupational hazards survey. Data from the Health and Nutrition Examination Survey are being used to develop a new estimate of the number of persons who have been exposed to asbestos and to relate x-ray abnormalities to other measures of lung function. Existing data, including vital statistics, are also being used to make estimates of the clinical significance of findings from other epidemiologic studies.